1. Field of the Invention
The present invention relates to a reactor to which a reactant is supplied, thereby causing reaction of the reactant.
2. Description of the Related Art
In recent years, a development has been underway to mount a fuel cell as a clean power supply with its high efficiency of energy conversion in automobiles or portable devices. The fuel cell is a device that causes a fuel and oxygen that is contained in an atmospheric air to react with each other in an electrochemical manner, thereby directly extracting electrical energy from chemical energy.
Although a hydrogen simplex can be exemplified as a fuel for use in a fuel cell, there is a problem in handling such a hydrogen simplex due to the fact that hydrogen is gaseous at a normal temperature and under a normal pressure. There has been an attempt to store hydrogen by a hydrogen storing alloy. Because a storage amount of hydrogen per unit volume is small, however, such an attempt has been insufficient as means for storing a fuel of a power supply of a small sized electronic device such as a portable electrical device in particular.
In contrast, there is provided, for example, a reformed fuel cell for reforming a hydrocarbon based liquid fuel to produce hydrogen, the cell having hydrogen atoms in a composition such as alcohol and gasoline. In such a reformed fuel cell, a fuel can be easily stored in a liquefied state.
Such a reformed fuel cell needs a reactor comprising a plurality of reaction devices including a vaporizer for vaporizing a liquid fuel and water; a reformer for removing hydrogen required for power generation by causing the vaporized liquid fuel and a high-temperature water vapor to react with each other; and a carbon monoxide removing unit for removing carbon monoxide that is a by-product of a reforming reaction.
In order to downsize the reformed fuel cell having such a configuration, and enable the battery to be mounted on a portable device or the like, a development has been underway with respect to, for example, a microreactor module having a vaporizer, a reformer, and a carbon oxide removing unit laminated with one another. In this case, metal substrates each having formed therein a groove or channel that serves as a flow channel for a fuel or the like are bonded so as to form the reactor.
In the meantime, in order to downsize a reacting unit while maintaining reaction efficiency in the reaction device, it is necessary to reduce sectional dimensions of the flow channel, thereby reducing a diffusion time of a reactant up to a catalyst provided on a surface of the flow channel and to increase a length of the flow channel, thereby increasing a reaction time. However, in order to reduce the sectional dimensions of the flow channel and to increase the length of the flow channel, it is necessary to form a fine flow channel that wobbles inside of the reaction device. In addition, it is necessary to provide a complicated flow channel structure in order to increase the length of the flow channel. That is, assembling becomes complicated.
In order to well carry out reaction in the reaction device, the reaction device is heated at a temperature suitable for such a reaction and is maintained at a predetermined temperature. In order to reduce a loss of thermal energy, a vacuum heat insulation structure is occasionally provided such that the periphery of the reaction device is established in a vacuum state. However, in the case where the thickness of metal substrates that configure the reaction device is reduced in order to reduce a weight of the reaction device, the rigidity of the reaction device is lowered. As a consequence, the reaction device is deformed or broken due to reaction caused by a pressure difference.